1. Field of the Invention
This invention relates to a packing for keeping watertight the boundary between articles such as connectors employed for connection of electric wires.
2. Description of the Related Art
Various electronic devices are loaded in a motor vehicle. To this end, a wire harness is arranged to supply a signal or power to the electronic devices. The wire harness includes a plurality of electric wires and a connector attached to the electric wires.
The connector includes terminal metal fittings connected to the electric wires and a connector housing for housing the terminal metal fittings. The wire harness supplies the prescribed signal or power to the various electronic devices in such a way that the connector housings are coupled with each other to connect the terminal metal fittings to each other.
The above connector can be provided with a packing 101 to waterproof the boundary between housings 102 and 103 as shown in FIG. 12 (see JP-A-2002-151189). The packing 101 is made of rubber serving as an elastic material and formed in a ring shape.
The one connector housing 102 which is a first article has a concave groove 104 in which the packing 101 is to be accommodated. It is now assumed that the packing 101 is accommodated in the concave groove 104. When the other connector housing 103 is coupled with the one connector housing 102, as shown in FIG. 12B, the one connector housing 102 is compressed by the outer face of the other connector housing 103 so that it is elastically deformed. The packing 101 makes watertight (also referred to “seal” or “waterproof”) the boundary between the inner face of the concave groove 104, i.e. the one connector housing 102 and the connector housing 103.
It is expected that the packing 101 surely waterproof the boundary between the articles such as the above connector housings 102 and 103. In order that the boundary between the articles is waterproofed, the packing 101 is compressed by a prescribed distance to be elastically deformed when the boundary between the articles is waterproofed.
On the other hand, the packing 101 employed for waterproofing the boundary between the connector housings has a round shape in section in an initial state where it is not still elastically deformed. When the packing 101 is elastically deformed as a result of having been compressed by a prescribed distance, its width is increased. As a result, the width of the concave groove 104 must be also increased. Thus, the connector housing 102 tends to be larger. However, it is of course demanded that the connector is smaller.
It is also demanded that the packing 101 is smaller. It can be therefore proposed that the packing is caused to have a width smaller than a thickness as shown in FIG. 13A. It can also be proposed that the width of the concave groove 104 formed in the one connector housing 102 is reduced so that the packing 101 has the elastic deformation enough to waterproof the boundary between the articles, thereby allowing the connector housing 102 to be smaller.
In this case, since the width is smaller than the thickness, when the articles are brought to each other so that the packing 101 is compressed in a direction of thickness, the packing 101 may fall or roll to one side as indicated by two-dot chain line in FIG. 13B. The contact face pressure between the packing 101 and the article cannot be kept so that the packing 101 can not surely waterproof the boundary between the articles.
Thus, a first object of this invention is to provide a smaller packing and surely waterproof the boundary between articles.
A second object of this invention is to provide a connector equipped with a smaller packing and surely waterproof the boundary between a connector housing and a complementary connector housing.